Lithium cell treating method

ABSTRACT

A treating fluid is in contact with a negative electrode containing lithium of a lithium cell under a first condition to react a surface portion of the negative electrode, and a treating fluid is in contact with lithium existing inside an article formed on the surface of the above-described negative electrode under a second condition. The cells can be effectively treated under safety condition to collect either the valuable substances, or the cell constructive components.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation-in-Part of application Ser. No.08/220,220 filed on Mar. 30, 1994, now U.S. Pat. No. 5,628,973.

BACKGROUND OF THE INVENTION

The present invention relates to a treating method and a treatingapparatus of a used cell or battery, and to a method and an apparatusfor treating a lithium cell.

Demands of cells or batteries are increasing year by year. Effectiveutilization of chemical substances employed in cells or batteries, andalso problems of environmental pollution caused by cells or batteriesmust be considered. For example, lithium and transition metal elementand the like employed in a lithium cell are variable substances to bereused. Rechargeable lithium secondary cells are extensively used yearafter year as backup power sources for computers and power sources forcompact home appliances. Other demands as power storage power sources,or power sources for automobiles may have a bright future.

High energy type cells typically known as lithium cells employelectrolytic solution containing negative-electrode activated substancessuch as reaction-activated alkali metals, and also substances reactiveto water. And most of positive electrodes include great deal of reusablemetal component. As a consequence, when used cells are dismantled, it isdesired to propose such a treatment method that cell-activatedsubstances, or activated substances such as electrolytic solution arebrought into inert substances under safety states, and reusable valuablechemical substances are collected. However, no confirmation could bemade about any method for treating a large number of cells such as usedlithium cells in an industrial scale, or any invention related to a celltreating apparatus.

To suppress environmental pollution caused by chemical substancescontained in used cells, or used batteries, and to improve utilizationof resources employed in these cells, cell treating methods as well asmethods for reusing cell materials have been required for long time.

Generally speaking, a specific care should be taken to handle suchhigh-energy density type cells as lithium cells, because these cellscontain cell activated substances or electrolyte with extremely highchemical reactive characteristics. For instance, carbon compounds intowhich a lithium metal, a lithium alloy, and lithium have been insertedby electrical and chemical methods, are utilized in a negative electrodeof a lithium cell, and therefore any of these compounds extremely reactsto water, thereby producing hydrogen gas. Also in the above describedcells, there are employed other than the above mentioned alkali metal,either valuable substances such reusable transition metals, orelectrolytic solution capable of probably producing poison gas. As anexample of the valuable substances, there are LiCoO₂, LiNiO₂, V₂ O₅ andthe like, which correspond to an activated substance of a positiveelectrode for a lithium cell. As an example of the electrolyticsolution, there are LiPF₆, LiAsF₆ and the like, which correspond to thetypical electrolyte of the lithium cell. The electrolytic solutioncontaining these electrolyte mediums is resolved with being cooperativeto water, thereby producing PF₅, AsF₅ and the like having strong poison.As a consequence, method/means capable of safely treating cells in ahigh efficiency are required.

SUMMARY OF THE INVENTION

Thus, an object of the present invention is to provide a cell treatingmethod and a cell treating apparatus with safety and high efficiencies.

The present invention is so featured that a cell constructed of apositive electrode and a negative electrode containing lithium viaelectrolyte is in contact with treating fluids which react to lithiumunder a first condition and a second condition.

It is also featured that the above-described negative electrodecontaining lithium is in contact with the first treating fluid reactingto lithium under the first condition, whereby a surface portion of thenegative electrode will react, and lithium existing inside the reactedmaterial, i.e. product, formed on the surface of the negative electrodeby means of the first treating fluid is in contact with the secondtreating fluid reacting to lithium under the second condition.

A cell treating method for adding a treating fluid to a cellmanufactured by providing a positive electrode and a negative electrodecontaining lithium via electrolyte within a cell vessel, ischaracterized by comprising step 1 for exposing the negative electrodecontaining lithium, step 2 for separating the electrolyte from the cell,and a step 3 for causing the treating fluid reacting to lithium to be incontact with the above-described negative electrode. In this treatingmethod, it is preferable to further comprise step 4 for collecting atleast one of the used treating fluid, the used electrolyte, and the usedcell constructive parts.

The step 3 is so featured that the negative electrode containing lithiumis in contact with the first treating fluid reacting to lithium underthe first condition, whereby the surface portion of the negativeelectrode will react, and lithium present within the product formed onthe surface of the negative electrode is in contact with the secondtreating fluid reacting to lithium.

As to the below-mentioned subjects, it is preferable to have such arelationship as the first condition<the second condition:

A relationship in concentration about of a reaction substance whichreacts to the negative electrode containing lithium within therespective treating fluids.

A relationship in water content within the treating fluid. For instance,a relationship in a concentration of water within the treating fluids.

A relationship in temperatures of the treating fluids.

A relationship in reaction velocity of reactions between the negativeelectrode containing lithium and the treating fluids.

A relationship in amounts of gas produced by causing the negativeelectrode to be in contact with the treating fluids.

A producing rate of hydrogen gas produced when the treating fluid is incontact with the negative electrode containing lithium. This gasproducing rate may be measured by measuring, for example, an amount ofhydrogen produced per unit time, or may be judged based on hydrogenconcentration and so on.

The above-described second condition is featured that the product formedon the surface of the negative electrode under the first condition iswashed, and lithium present within the product is in contact with thetreating fluid reacting to lithium. The washing process may be carriedout by, for instance, melting the product formed on the surface, orpeeling off the product from the negative electrode.

In the above-described step 3, the treating fluid is in contact with thenegative electrode and this treating fluid may be stirred.

In the above-described step 1, at least one of the above-explained cellvessel and positive electrode is separated from the cell, so that thesucceeding steps may be effectively executed.

If a binder is used to bind active material powder particles to currentcollector, it is preferable to dissolve said binder so as to collectsaid active material powder by treating the electrodes with a solventcapable of dissolving the binder. If said binder is a fluorine resinsuch as a polyvinylidene fluoride, or a rubber such as a natural rubber,a styrene.butadiene rubber, a polybutadiene rubber or the like, anorganic solvent such as a polar solvent, for example,1-methyl-2-pyrrolidone, a hydrocarbon solvent, for example, cyclohexane,or an aromatic solvent, for example, xylene can be preferably used. Thistreatment also accelerates the reaction speed between the activematerial powder particles and a treatment fluid to be used thereafter.

As the step 2, either the cell, or the constructive parts of the cell isin contact with a fluid for cleaning electrolyte. For instance, afterthe cell, or the constructive part thereof is dipped into the cleaningfluid, or the cleaning fluid is supplied to this cell, or theconstructive part thereof in order to be in contact with it, thecleaning fluid is collected to separate the electrolyte from the cell.

The above-explained treating fluid may contain one or more sorts ofreaction substance which react the negative electrode containinglithium. An organic fluid, water or a mixture of water with said organicfluid can be used as a treating fluid. Any organic fluid can be used asa treating fluid as far as said organic fluid can produce an inactiveorganic lithium compound as a result of reaction with lithium. A polarorganic solvent such as an alcohol, an organic acid such as acetic acid,oxalic acid, formic acid, etc., or the like can be illustrated as anorganic fluid for the treatment. Among alcohols, an aliphatic alcoholwhose carbon atoms is 5 or less such as, ethanol, propanol or butanol ora mixture thereof can be preferably used. More preferably, ethanol,propanol and butanol can be used.

A polar organic solvent can be used as a mixture with a water for thetreatment. Such a mixture can be prepared by mixing said polar organicsolvent with water within in a range of from 0.99:0.01 to 0.01:0.99 byweight.

When such a mixture is used for a treatment just after the exposure ofthe electrodes by destroying spent lithium cells, it is preferable touse a polar organic solvent-rich mixture for such a treatment becausethe electrode to be treated is rich in lithium. It is also preferable touse a polar organic solvent alone for such a treatment so as to reducethe formation of hydrogen gas as much as possible. Indeed, a mixture ofpolar organic solvents can be used for that purpose, too.

The preferable ratio between the polar organic solvent and water is0.95:0.05 to 0.55:0.45 by weight for such a treatment while the amountof the polar organic solvent may vary, depending upon the reactivity ofthe chosen polar organic solvent with lithium.

It is preferable to choose a proper ratio between two, taking intoconsideration the reactivity of the chosen polar organic solvent andlithium, and the reactivity of water with lithium.

If an alcohol having carbon atoms of 4 or less such as, ethanol,propanol or butanol is used as a polar organic solvent, such a ratiobetween the polar organic solvent and water can be chosen within a rangeof from 0.99:0.01 to 0.9:0.1 by weight.

That is, the amount of water in the mixture should be kept at the levelof 10% or less weight for the treatment of newly exposed electrodesbecause the reactivity of said polar organic solvent with lithium isusually one tenth or less than that of water with lithium.

As the lapse of the time, reaction products between lithium and the saidtreatment fluid, such as lithium alcoholate salts, are accumulated onsurface of electrodes, or the said treatment fluid is not so permeativeinto the bulk of electrodes as enough to react with lithium remaining inthe said electrodes. In order to keep a similar reaction speed, it ispreferable to add water to the treatment fluid so as to increase theamount of water or a water-rich mixture can be used as a second treatingfluid after the removal of a first treating fluid; thus, the reactivitycan be retained at a desirable level. That is, one may choose a mixtureof a polar organic solvent and water having the ratio of from 0.5:0.5 to0.05:0.95 by weight, depending upon the development of the treatment bychanging the treating liquid or adding water to the treating liquid. Atthe last stage, one may add water in an amount enough to react withlithium for safety if there is a possibility that lithium still remainsin the electrodes, or one may use only water after removing the treatingfluid contains said protonic organic solvent.

The above-described treatment is performed in such a featured mannerthat this treatment is carried out either in inert gas, or in a dry gasatmosphere having a moisture content than that of air.

Furthermore, based upon at least one of information about temperatures,heating amounts, infrared, gas compositions, and pressure, the supplyamount of at least one of the above-explained electrolyte cleaningfluid, treating fluid, inert gas, and dry gas may beincreased/decreased, or stopped. At least one of compositions of thetreating fluid, inert gas, and dry gas may be adjusted.

For instance, while monitoring an amount of production of hydrogen, thecompositions of the treating fluid to be supplied, or the supply amountof the treating fluid may be controlled to achieve a predeterminedreaction condition, so that lithium contained in the negative electrodemay be treated. The concentration of the hydrogen gas generated in atreating chamber should be kept constantly at a level of 4% or below forthe safety operation. The temperature of the treating chamber should bekept at a temperature under 100° C., e.g., from 20° C. to 80° C.,preferably 40° C. or less.

Also, the present invention is characterized by comprising at least atreating chamber having supply means for supplying an inert gas or a drygas whose moisture content is lower than that of air, and treating meanswithin the treating chamber, for contacting more than two sorts oftreating fluids reacting with lithium to the negative electrode of alithium cell. Alternatively, the present invention is characterized bycomprising more than two treating means within the treating chamber, forcontacting at least one sort of treating fluid reacting to lithium tothe negative electrode of the lithium cell.

Concretely speaking, the present invention is characterized bycomprising a chamber having supply means for supplying an inert gas or adry gas whose moisture content is lower than that of air; the treatingchamber being connected via means for keeping gas atmosphere of thetreating chamber to a preparing chamber equipped with an input/outputport for a cell or a cell constructive part, and both the treatingchamber and the preparing chamber including transporting means of thecell or the cell constructive part; resolving means for exposing anegative electrode containing lithium from a lithium cell along thetransporting means within the treating chamber, the lithium cell beingconstructed of a positive electrode and the negative electrodecontaining lithium; separating means for separating electrolyte bycontacting the cell to a fluid for cleaning electrolyte; and treatingmeans for contacting the exposed negative electrode to a treating fluidreacting with lithium under more than two sorts of conditions.

The treating means is featured that the treating means includes asupplying port of a fluid reacting to lithium and a exhausting port ofthe fluid, provided in a downstream of the supplying port, the supplyingport is communicated to a tank for storing a fluid reacting to lithiumvia either a switching valve for controlling the supply amount of thefluid from the tank, or a flow amount controller, and the exhaustingport is communicated with a storage unit for the used liquid which hasbeen collected at the exhausting port. At least one piece of theabove-described tank is provided into which at least one sort of organicfluid, water, and mixture thereof is stored.

The supplying port is installed from a bottom surface of the treatingchamber via a predetermined space, and the exhausting port is providedat a lower position than that of the supplying port. Preferably, morethan two sets of treating means are employed. Also, more than two setsof treating means are arranged in a series form with respect to thetransporting means.

It above-described gas atmosphere keeping means may employ, forinstance, a port, or an air curtain on which a switching means isprovided.

Furthermore, the present invention is characterized in that at least onesensor is provided at a preselected place within the treating chamber,and a controlling apparatus is provided which selects and controls atleast one of supply component compositions and supply amounts for theinert gas, dry gas, liquid to clean electrolyte, and liquid reacting tolithium in response to information from the sensor. An inert substanceand the like are separately stored, and the inert substance maybesupplied when the sensor senses an extraordinary condition.

The above-explained sensor may sense at least one of various types ofinformation about temperatures, heating amounts, infrared, gascompositions, and pressure. The sensor may be properly selected fromsuch sensors capable of sensing physical and chemical conditions of acell.

The above-described control apparatus is characterized by comprising acalculation control unit for calculating information derived from thesensor, a memory unit for storing therein either past calculated data,or separately inputted data, and a control unit for comparing the valuecalculated by the calculating control unit with the data stored in thememory unit, thereby controlling at least one of supply amounts andsupply component compositions with respect to more than one of theabove-described inert gas, dry gas, liquid to dissolve electrolyte, andliquid reacting to lithium. Preferably, at least one of measurementdata, calculation program, calculation data of the sensor is stored inthe memory unit.

The cell treating apparatus, according to the present invention, hassuch a construction that the preparing chamber capable of supplyingeither the inert gas or the dry gas is coupled to the treating chamberfor treating the activation substances of the cell under the inert gasor the dry gas atmosphere whose moisture content is lower than that ofair. In the cell treating chamber, the fluid supplying system of thetreating fluid is connected to the fluid exhausting system thereof.Since the inflammable gas such as hydrogen gas and the poison gas suchas PF₅ are produced while treating the cell, the gas exhausting systemis installed together with the gas supplying system. To transport thecells and the cell constructive parts between the treating apparatus andthe outside field, and/or within the treating apparatus, the gasatmosphere keeping means within the respective chambers are providedbetween the preparing chamber and the outside field of the treatingchamber, and between the adjoining preparing chambers and the treatingchamber. For instance, either a switching plate, or a transporting portis employed. When the switching plate is utilized, the supplying systemof the dry gas and the exhausting system thereof, which have valves, arerequired. When the transporting port is used, a method for continuouslypassing the dry gas and the like within the preparing chamber isemployed. When the cell is entered from the outside field into thetreating apparatus, or when the cell is transported among the treatingchambers for the different gas atmospheres, it is possible with such abasic structure to keep the gas atmospheres of the treating chambers.

Next, a description will be made of the inert treating process for theused cells with employment of the above-explained treating fluid andtreating apparatus for cells. As a concrete example, the cell treatingmethod of the present invention comprises step 1 for exposing thenegative electrode of the cell; step 2 for separating either theelectrolytic fluid, or the solid electrolyte from the cell; step 3 forcontacting the treating fluid to the negative electrode; and step 4 forcollecting the disposal treating fluids, the electrolyte fluid or solidelectrolyte the cell constructive parts, and the disposal membersthereof.

At the step 1, the lithium cell may be completely discharged bypreviously connecting the positive polarity terminal of this lithiumcell via a resistor or the like to the negative polarity terminalthereof. Furthermore, the lithium cell is transported to the preparingchamber of the cell treating apparatus according to the presentinvention, in which air present in this chamber is substituted by drygas and the like. Subsequently, the lithium cell is transported fromeither the switching plate, or the transporting port provided betweenthe preparing chamber and the treating chamber, into the treatingchamber of the lithium cell. Next, a selection is made of a method fordestroying the vessel of the lithium cell, depending upon the size ofthe lithium cell to be treated. In case of a small-sized cell, this cellmay be dipped into an acid solution to corrode the cell vessel, and/orthis cell may be mechanically crashed by employing a hammer crusher. Incase of a large-sized cell, this type of cell may be destroyed in such amanner that the upper portion of the cell vessel is cut by a diamondcutter, to take out the cell constructive parts such as the electrodesfrom the vessel. When the electrodes of the large-sized cell are crashedby a cutter mixer, the time period required for the step 3 may beshortened (will be discussed later).

In the step 2, the electrolyte fluid or the solid electrolyte existingin the cell vessel, and the electrolytic fluid soaked in the separatorcan be collected. The electrolytic fluid remaining in the vessel can becollected by way of the disposal fluid exhausting system connectedthereto. The electrolytic fluids attached to the cell vessel, the cell,and the separator may be cleaned by inert organic solvent such as benzenand the hexane, and then the resulting cleaning fluids may be collectedfrom the disposal fluid exhausting system. When the electrolytic fluiddirectly collected, and the electrolytic fluid collected by the cleaningprocess, are separately collected from the different exhausting systems,it is useful to reduce reuse cost of the electrolytic fluid at the step4 (will be discussed later).

In the step 3, the negative electrode is treated by using the treatingfluid. As examples of usable treating fluid, there are alcohol such asethanol, methanol, and propanol, a mixture fluid of alcohol and water,and water. These treating fluids react with the negative-electrodeactivated substances such as carbon containing a lithium metal, alithium alloy, and lithium. When the water containing composition of thetreating fluid is increased, reactive characteristic thereof becomeshigh. When a large quantity of lithium metals and compounds thereof aretreated at once, there is a risk that a large amount of hydrogen may beproduced due to reaction between lithium and alcohol even when onlyalcohol is used. In this case, mixture of above-described lower alcoholand the inert organic solvent to lithium is used so as to reduce thereactive characteristic of alcohol with respect to lithium. As theabove-described inert organic solvent, there is hydrocarbon having morethan 5 carbon numbers such as pentan, hexane, and benzen.

The treating fluid is conducted from the fluid supplying system, and thenegative electrode is contacted with this treating fluid. Variousmethods for dipping the negative electrode into the treating fluid, forspraying the treating fluid toward the negative electrode in a sprayshape, or for applying the treating fluid to the negative electrode maybe utilized. When alcohol is first in contact with the negativeelectrode, lithium alcoholate is solved into a liquid phase, and aportion of this solved lithium alcoholate is deposited on the surface ofthe negative electrode. Gradually, the surface of the negative electrodeis covered with the alcoholate deposited layer. The treating liquid iseither heated, or stirred, thereby solving or separating theabove-described alcoholate layer into or from the liquid phase, so thatit is possible to prevent that the treating fluid is reacted with thenegative-electrode activated substance located within the negativeelectrode, which is not yet reacted. As other means, either water, or awater/alcohol solution having a large water containing amount isattached to the negative electrode, and an alcoholate layer covering thenegative electrode is solved, whereby resolving reaction of thenegative-electrode activated substance which has not yet been reacted,is emphasized. A decomposition velocity of the negative-electrodeactivated substance may be controlled within a proper range by adjustingthe temperature and the stirring rate of the treating fluid, and alsothe water containing amount of the treating fluid. As a result, the celltreating time may be shortened.

When a lithium cell is treated, it is preferable to employ such a celltreating apparatus that a plurality of treating chambers having thesupplying ports and the exhausting ports for the treating fluid arealternately coupled to the preparing chambers. After the activatedsubstances of the lithium cell have been decomposed in a treatingchamber, the decomposed cell is moved to the adjoining treating chamber.Subsequently, all activated substances are decomposed by employing thetreating fluid with a stepwise high reactive characteristic. Also evenwhen source of the treating chambers are segmented, a plurality of fluidsupplying ports and fluid exhausting ports are mounted on the segmentedtreating chambers, and the treating times of the cell within onetreating chamber are increased, the cell treating time period maybeshortened. Gas atmospheres in the respective treating chambers arepreferably dried up to the water concentration of the treating fluid tobe used.

The used disposal treating fluid is exhausted from the treating chamberby the liquid exhausting system and then stored into a disposal treatingfluid storing vessel. Hydrogen gas produced during the treatment of thenegative electrode is preferably exhausted together with the dry gasexisting in the treating chamber from the treating chamber by the gasexhausting chamber. A gas separator is installed in the gas exhaustingsystem to separate hydrogen gas from inert gas, so that both of thehydrogen gas and the inert gas may be reused. When the electrolyticfluid containing LiPF₆ and LiAsF₆ is decomposed, such a treating fluidthat water is diluted by alcohol is used. When the above-describedelectrolyte is reused, the separator is cleaned by the inert organicsolvent such as benzen and hexane, and the electrolyte may be collectedby vaporing it.

In the step 4, the treated cell constructive parts are derived from thepreparing chamber located at the end portion of the cell treatingapparatus, and the heavy metals may be reused by way of the previouslyestablished melting refinery method. From the collected electrolyticfluid and disposal treating fluid, the electrolyte such as LiPF₆ andLiAsF₆, the poison elements such as As the lithium metal may becollected. The cost to collect the valuable substances from the usedtreating fluid is influenced by concentrations of subjective substancescontained in the disposal fluids exhausted from the cell treatingapparatus. For instance, there is a case that the lower the containingconcentration of the subjective substance becomes, the higher thecollecting cost by the condensing process is increased. In accordancewith the cell treating apparatus of the present invention, the disposaltreating fluids exhausted from the respective treating chambers areseparated and collected by employing the different disposal treatingfluid exhausting systems, and the condensing process is performed onlyto the treating fluids containing the valuable substances at lowerconcentrations, so that the valuable substances can be collected fromall the disposal treating fluids at lower cost. Also, depending upon thesorts of valuable substances, only the disposal fluids with highdensities may be reproduced and treated, and the remaining disposalfluids may be treated by the normal disposal method. As described above,according to the cell treating apparatus of the present invention, thedisposal treating fluids of the valuable substances with the differentconcentrations can be separately collected, whereby the cost of thereproducing process for the valuable substances can be reduced.

When the above-described cell treating steps would be automaticallyperformed, the cell treatment could be performed at high efficienciesand also safety matters about the cell treatment could be improved. Whensuch a driving type transporting machine as a belt conveyer would beprovided in the preparing chamber and the treating chamber,transportations of cells could be easily performed between the preparingchamber and the treating chamber. When there would be provided aswitching valve, or a flow rate controller for controlling the supplyingamounts and the exhausting amounts of the treating fluid and gas;sensors for measuring pressure, temperatures, heating amounts, infrared,and gas compositions such as hydrogen concentration within the treatingchamber; and also a controlling apparatus for controlling the flow ratecontrollers of the treating fluid and gas in response to the conditionsof the treating chamber monitored by the sensors, the gas atmosphereswithin the cell treating apparatus could be automatically maintained,and also the supplying amount of the treating fluid could beautomatically controlled. The flow rate controller and the like areprovided on the intermediate portions of the treating fluid supplyingtube and the treating fluid exhausting to be, which are connected to thepreparing chamber and the treating chamber of the cell treatingapparatus. The sensors are installed inside the treating chamber, and atemperature sensor, an infrared sensor, or a hydrogen sensor may beemployed as these sensors. The measurement data about the temperaturedistribution, and hydrogen concentration within the treating chamber aretransferred from the sensors to the controlling apparatus. For example,in the controlling apparatus, the information derived from the sensorsis analyzed by the calculation processing unit and the controlling unit,the flow rate controller is operated in response to the analyzedmeasurement data, so that the supplying amount of the treating fluid, orthe inert gas, the composition thereof, and the exhausting amountthereof are adjusted. A memory for storing therein the past data, theseparately inputted data, and the program may be provided. Then, theflow rate controller may be operated by comparing the supplying amountof the treating fluid or the dry gas with the exhausting amount thereof,whereby the supplying amount and the exhausting amount of the treatingfluid or the dry gas maybe adjusted. When rapid decomposition reactionhappens to occur during the treating process of the cell, the conductionof the treating fluid may be instantaneously interrupted. Also, suchinflammable gas as hydrogen gas which is excessively produced may bequickly exhausted from the cell treating apparatus. Moreover, a failureoccurred during the cell treating process may be prevented in advance bypreviously storing the measurement data acquired before and after thecell treatment in the past into the memory unit of the calculationcontroller, by predicting rapid reaction occurred between the activatedsubstances of the cell and the treating fluids based upon comparisonsbetween the present measurement data and the past measurement data, andby controlling the supplying amounts of the treating fluids and the drygas, and the exhausting amounts thereof. The operations of the celltreating apparatus could be automated by incorporating such a controlsystem into the cell treating apparatus, with the result that thedecomposition process of the cell may be performed at higherefficiencies under safety conditions.

As described above, with employment of the apparatus according to thepresent invention, the lithium cells can be resolved in safe way, andeither the cell activated substances, or the electrolytic fluid can bebrought into inert conditions at higher efficiencies. Also, the disposaltreating fluids may be easily separated and collected, so that thevaluable substances contained in the cell could be effectively recycled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a secondary battery treating apparatusaccording to the present invention.

FIG. 2 is a schematic diagram of a secondary battery treating apparatuscomprising a slide type switching plate.

FIG. 3 is a schematic diagram of a secondary battery treating apparatus,according to the present invention, in which two treating chambers areseries-connected to three preparing chambers.

FIG. 4 is a schematic diagram of a secondary battery treating apparatus,according to the present invention, in which a single treating chamberis segmented by two compartment plates.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

FIG. 1 is a cell treating apparatus where one treating chamber 1 iscoupled to two preparing chambers 2a and 2b on both sides thereof, whichcorresponds to a basic construction of the present invention. Outerdimensions of the treating chamber 1 and the preparing chambers 2a, 2bare 1 m×1 m×2.5 m, and 0.5 m×0.5 m×1 m respectively. The preparingchambers 2a and 2b own switching plates 3a and 3b at outer sides thereofto maintain airtightness of the preparing chambers. There are also twosheets of switching plates 4a and 4b between the preparing chambers 2a,2b and the treating chamber 1. To transport a cell, cell constructiveparts and so on inside this treating apparatus, a belt conveyer 5 isinstalled. Three sets of gas supplying systems are connected to thetreating chamber 1 and the preparing chambers 2a and 2b, which comprisea nitrogen gas storage vessel 6 having a function to dry gas, nitrogengas supplying tubes 7a, 7b, 7c, and switching valves 8a, 8b, 8c. Thetreating chamber 1 is connected via a gas exhausting tube 10 with a gasseparator 9, and the switching valve 8d is fixed to the gas exhaustingtube 10. To return nitrogen gas collected by the gas separator 9 to thestorage vessel 6, a transport tube 11, a gas transport pump 12, and aswitching valve 8e are employed, and the gas generated in the treatingchamber 1 during the cell treatment is separated by the gas separator 9,so that the generated gas is collected into a generated gas storagevessel 14 connected by a transport tube 13 having a switching valve 8f.When hydrogen gas is collected, a hydrogen absorbing alloy is put intothe generated gas storage vessel 14. While the cell is treated, theswitching valve 8b, the switching valve 8d, and the switching valve 8eare brought into opening states, and then the pump 12 is driven tocirculate nitrogen. The cells to be treated in this embodiment 1 arefive pieces of cylindrical type 3 Wh lithium secondary batteries inwhich LiCoO₂ is employed as a positive electrode, an Li alloy is used asa negative electrode, and an organic electrolytic fluid into which LiPF₆is solved is employed as electrolytic solution. First, these cylindricaltype secondary batteries are completely discharged outside the celltreating apparatus. The switching plate 3a is opened to position theabove-described cells 15 into the preparing chamber 2a, and theswitching plate 3a is closed. Next, a switching valve 17a mounted on thegas exhausting tube 16a is opened and an exhausting pump 18a is actuatedto exhaust air present in the preparing chamber 2a. After the preparingchamber 2a becomes a vacuum, the switching valve 17a is closed and thepump 18a is stopped. Subsequently, dry nitrogen gas is supplied from thegas supplying tube 7a to the preparing chamber 2a. Thereafter, theswitching plate 4a is opened to transport the cells 15 to the treatingchamber 1, and a switching door 4a is closed. The vessels of the cells15 are crashed within the treating chamber 1 by employing a cellcrashing machine 19 having a hammer crusher, and the crashed articlesare collected into a storage vessel 20 with a mesh provided on a bottomthereof. Hexane is used to clean the electrolytic fluid adhering to thecrashed articles. A treating fluid storage vessel 21a for storing hexaneis connected to the treating chamber 1 by way of a fluid supplying tube25a equipped with a switching valve 22a, a pump 23a, and a sprayer 24a.Hexane is sprayed from the sprayer 24a toward the crashed articlesstored in the storage vessel 20, thereby cleaning up the electrolyticfluid, and then the used cleaning fluid is stored into a disposal fluidstorage vessel 28a via a fluid exhausting tube 27a mounted on theswitching valve 26a. Thereafter, the storage vessel 20 was transportedunder the sprayer 24b. The switching valve 22b is opened to operate thepump 23b, and ethanol stored in the treating fluid storage vessel 21bwas sprayed toward the crashed articles. When ethanol is added to thenegative electrode, the lithium alloy was started to be decomposed andhydrogen gas was produced. Since a large amount of white lithiumalcoholate was deposited on the surface of the negative electrode afterapproximately 25 minutes have passed, reaction velocity between thenegative electrode and ethanol was decreased, and the rate of generatinghydrogen gas was lowered up to 30 ml or less per minute. The generatedhydrogen gas was exhausted via the gas exhausting tube 10 together withnitrogen gas until the gas separator 9. In the gas separator 9, nitrogenwas collected and nitrogen gas was transported via the transport tube 11to the gas storage vessel 6. The hydrogen gas was stored from the gastransport tube 13 into a hydrogen storage vessel 14 containing LaNi₅ byopening the switching valve 8f. Since the generation of hydrogen fromthe destroyed articles was not observed after ethanol had been added andapproximately 45 minutes have passed, the disposal treating fluid wastransported from the fluid exhausting tube 27b to the disposal treatingfluid storage vessel 28b by opening the switching valve 26b. When theinside of the preparing chamber 2b is not filled with dry nitrogen, thegas present within the preparing chamber 2b was exhausted by way of agas exhausting system equipped with a switching valve 17b, a pump 18b,and a gas exhausting tube 16b. After the switching valve 17b is closed,the switching valve 8c is opened to conduct dry nitrogen from the gassupplying tube 7c into the preparing chamber 2b. The storage vessel 20for storing ethanol-treated crashed articles was transferred to thepreparing chamber 2b after the preparing chamber 2b has been filled withdry nitrogen, and the switching plate 3b was opened after the switchingplate 4b was closed, thereby taking out the crashed articles. With theabove-described operations, total time required to treat 5 pieces of 3Wh lithium secondary batteries 15 was about 1.6 hours. The volume of theethanol solution containing lithium ion, collected in the disposaltreating fluid storage vessel 28b was 4.5 to 5 l. 80% of the lithiummetal used in the lithium cells was collected by way of the electricrefinery. 95% of LiPF₆ could be collected by vacuum-evaporating thehexane solution of LiPF₆ stored in the disposal treating fluid storagevessel 28a.

Embodiment 2

Five lithium secondary batteries with the above-described specificationare prepared, and a heater 29 shown in FIG. 1 is energized, so that thecell treating time is shortened by utilizing the apparatus of FIG. 1. Atreating fluid for the Li alloy negative electrode is ethanol and atreating fluid for collect the electrolyte solution is hexane. The cellsare crashed by employing the battery crashing machine 19 comprising thehammer crasher in accordance with the same sequence as that of theembodiment 1, and the crashed cell parts are stored into the storagevessel 20. Hexane was supplied from the sprayer 24a to clean the crashedcell parts. The disposal cleaning fluid was stored in the vessel 28a.Subsequently, the storage vessel 20 was positioned just under thesprayer 24b. First, the heater is turned OFF, and ethanol 1.5 to 2 l atthe room temperature was supplied from the sprayer 24b. Subsequently,the heater is turned ON, and ethanol 1 l at 50° C. was sprayed to thecell parts. The time required to execute the reaction becomes 25 to 30minutes, and total treating time became approximately 1.3 hours, wherebyabout 20 minutes can be shortened. An amount of hydrogen absorbed by thehydrogen storage vessel during the treatment of the negative electrodeis within a range from 50 ml to 150 ml per minute, and the negativeelectrodes could be continuously discomposed in accordance with themethod of this embodiment.

Embodiment 3

Instead of the method for heating the ethanol treating fluid executed inthe embodiment 2, the treating fluid is stirred so that the celltreating time can be shortened. With employment of the apparatus of FIG.1, five lithium secondary batteries having the same specification as inthe embodiment 1 were treated. The cells were crashed by the cellcrashing machine 19 equipped with the hammer crusher in the treatingchamber 1 in accordance with the same sequence as that of the embodiment1, and the cell articles crashed by the cell crashing machine 19 werestored into the storage vessel 20 having the bottom. After the cellconstructive parts and the cell vessels have been cleaned by hexanesupplied from the treating fluid storage vessel 21a in a similar mannerto that of the embodiment 1, ethanol 1 l is sprayed from the sprayer 24btoward the crashed articles and ethanol is stored into the storagevessel 20. Alternatively, the sprayer 24b connected to the treatingfluid supplying tube 25b is disconnected therefrom, and ethanol maydirectly flow from the end portion of the supplying tube 25b into thestorage vessel 20. Next, a rotary type stirring machine (not shown) wasinserted into the storage vessel 20 into which ethanol and the cellcrashed articles had been entered, to stir ethanol. Although an amountof ethanol required to treat the cells was 1 l, decomposition timeeffected by ethanol was 35 to 40 minutes, so that the cell treating timecould be shortened by stirring the treating fluid, as compared with thatof the embodiment 1.

Embodiment 4

The switching valve 22b provided in the cell treating apparatus shown inFIG. 1 was replaced by a flow-rate controller 22b having a function tocontrol a flow rate of a fluid, and the supply of the treating fluidduring the cell treatment was automatically controlled. A sensor(hydrogen sensor) 34 having a function capable of detecting hydrogenconcentration within the treating chamber 1 was installed in thetreating chamber 1. The sensor 34 was connected via a signal input cable35 to the calculation controller 36. The calculation controller 36, theflow rate controller 22b, and the treating fluid transport pump 23b weremutually connected by signal output cable 37a and 37b. The sensor 34measures hydrogen concentration within the treating chamber 1, andtransfers an electric signal directly proportional to the measurementvalue to the calculation controller 36. The calculation controller 36calculates the electric signal sent from the sensor 34, and transfers anelectric signal produced in accordance with this calculation result toeither the flow rate controller 22b, or the treating fluid transportpump 23b, thereby controlling these operations. In this embodiment, thecalculation processing conditions have been set in such a manner thatthe calculation controller is operable as follows:

(1) When the electric signal transferred from the hydrogen sensorsuddenly exceeds the above-described set value, the flow rate controller22b is closed via the signal output cables 37b and 37a to stop thetreating fluid transport pump 23b, thereby interrupting the supply ofthe fluid. An upper limit value of hydrogen concentration set in thisembodiment is a value corresponding to hydrogen concentration equal to ahydrogen generating amount of 200 ml per minute. That is, theconcentration of hydrogen gas generated in the treating chambercorresponds to 3%.

(2) When hydrogen concentration within the treating chamber 1 isgradually increased, the electric signal is set to the signal outputcable 37b to control the flow rate controller 22b, so that the flow rateof the treating fluid is reduced. Conversely, when hydrogenconcentration is low, the flow rate of the treating fluid is increased.In this embodiment, the flow rate of the treating fluid to be suppliedwas linearly increased/decreased within a range of 50 to 0 ml per minuteunder such a condition that the hydrogen generating speed corresponds tohydrogen concentration of 0 to 200 ml per minute.

Under the above-described conditions, the five lithium secondary cellshaving the same specification as in the embodiment 1 were treated byemploying the apparatus of FIG. 1, and the amount of ethanol suppliedfrom the treating fluid storage vessel 21b was 4 l. 1.4 to 1.5 hourswere needed since the cells were entered into the treating apparatus andthen the treated crashed articles and the treated parts were derivedfrom the treating apparatus. In accordance with this embodiment, thecell treating time could be shortened and the amount of the usedtreating fluid could be lowered, as compared with the embodiment 1, andalso the cell treatment may be automatically performed without any manpower.

Embodiment 5

As the sensor 34 of the cell treating apparatus shown in FIG. 1, eithera temperature sensor, or an infrared sensor having a function capable ofsensing infrared rays was mounted, and five cylindrical type lithiumsecondary batteries having the same specification as in the embodiment 1were treated. Other than the used sensor, the switching valve 22b shownin FIG. 1 was replaced by a treating fluid flow-rate adjuster 22b in thecell treating apparatus employed in this embodiment. An internaltemperature of the treating chamber 1 is measured by the sensor 34(temperature sensor), and an electric signal directly proportional ofthe measurement value is transferred to the calculation controller 36.The sensor monitors infrared rays existing in the storage vessel 20 forstoring the negative electrodes of the crashed cells and around thestorage vessel 20, and transfers an electric signal directlyproportional to intensity of infrared rays to the calculation controller36. The calculation controller 36 executes a calculation process inresponse to the electric signal sent from the sensor 34. For example,when the temperature sensor is employed, if the internal temperature ofthe treating chamber 1 is increased within the range from the roomtemperature to 40° C., then the calculation controller 36 transfers theelectric signal via the cable 37a to the flow rate controller 22b inorder to lower the flow speed of the treating fluid stored in thetreating fluid storage vessel 21b from 50 ml per minute to 0 ml perminute. If the internal temperature of the chamber 1 exceeds 40° C., thecontroller 36 performs to close the flow rate controller 22b and totransfer the electric signal via the cable 37b to the pumps 23b in orderto stop the pump 23b. When the infrared sensor is utilized, whenintensity of infrared rays existing around the storage vessel 20 isincreased, the flow rate controller 22b is controlled, as previouslystated, to increase/decrease the flow speed of the treating fluid.

With employment of the cell treating apparatus of FIG. 1 comprising thetemperature sensor, when the above-described lithium cells were treated,the supply control of the treating fluid sharply sensitive to thetemperature changes during the cell treatment could be performed inresponse to local heating during the cell treatment if the infraredsensor is employed.

Embodiment 6

FIG. 2 is a cell treating apparatus in which the switching plates 4a and4b of FIG. 1 have been substituted by transfer ports 4a and 4bcomprising slide type switching plates, respectively, in order toshorten cell treating time, as compared with that of the embodiment 1.In this apparatus, dry air is used in the gas storage vessel 6, so thatthe dry air could be continuously supplied to the treating chamber 1.When the switching plate 3a is opened, the dry air is blown from the gassupplying vessel 31a into the preparing chamber, and then is passedthrough the gas exhausting tube 33a while the switching valve 32a isbeing opened, whereby wet air existing outside the apparatus could behardly mixed with the dry air in the treating chamber 1. Also, when thetreated cell constructive parts were derived from the preparing chamber2b, the dry air was blown from the gas supply vessel 31b into thepreparing chamber 2b, and was passed through the gas exhausting tube33b, while the switching valve 32b is being opened. Five lithiumsecondary batteries with the same specification as in the embodiment 1were prepared and treated by employing the heater 29 in a similar mannerto that of the embodiment 2. The time required to treat the negativeelectrodes by way of ethanol was 25 to 30 minutes similar to that of theembodiment 2, and there was no change in the crashing time of the cells.Since gas substitutions of the preparing chambers 2a and 2b were nolonger required in this embodiment, the overall treatment time could beshorted to become 1 hour.

Embodiment 7

Five pieces of cylindrical type 3 Wh lithium secondary batteries inwhich V₆ O₁₃ is used as a positive electrode, a Li metal is used as anegative electrode, and LiCF₃ SO₃ is mixed with polyethylene oxide assolid polymer electrolyte, were treated by utilizing the cell treatingapparatus of FIG. 1. The lithium secondary batteries with using theabove-explained solid polymer electrolyte were crashed within thetreating chamber 1 of FIG. 1, and the crashed articles were stored intothe storage vessel 20. In this embodiment, the crashed articles were notwashed by hexane, but were directly transported under the sprayer 24b.Subsequently, ethanol supplied from the treating fluid storage vessel21b was sprayed toward the crashed articles to decompose the Li metalcontained in the crashed articles. In accordance with this embodiment,ethanol was consumed by 4 l to treat the Li metal of the negativeelectrodes, and the treating time was 1.2 to 1.3 hours.

Embodiment 8

FIG. 3 is a cell treating apparatus in which two treating chambers 1aand 1b are alternately coupled to three preparing chambers 2a, 2b and2c. Outer dimensions of the treating chambers 1a and 1b are 1 m×1 m×2.5m, respectively, and outer dimensions of the preparing chambers 2a, 2b,2c are 0.5 m×0.5 m×1 m, respectively. Switching plates 3a and 3b areprovided outside the preparing chambers 2a and 2c to maintainairtightness of the preparing chambers. Four switching plates 4a, 4b,4c, 4d are located at portions where the treating chambers are incontact with the preparing chambers. This apparatus is equipped with anitrogen gas storage vessel 6 having a function to dry gas, and suppliesdry nitrogen to the respective treating chambers and preparing chambers.Gas supplying tubes for feeding dry nitrogen to the treating chambers1a, 1b, and the preparing chambers 2a, 2b, 2c, are 7b, 7d, 7a, 7c, 7e.Switching valves 8b, 8d, 8a, 8c, and 8e were mounted on the respectivesupply tubes. The treating chambers 1a, 1b and a gas separator 9 weremutually connected to each other by gas exhausting tubes 10a and 10b,and a switching valve 8g or a switching valve 8h was mounted on thehalfway of each gas exhausting tube. The gas generated in the treatingchambers 1a and 1b during the cell treatment and the nitrogen gas areseparated from each other by the gas separator 9. The nitrogen gascollected by the gas separator 9 is returned to the storage vessel 6,and a transport tube 11, a gas transport pump 12, and a switching valve8e were provided. The generated gas which had been separated wascollected by a generated gas storage vessel 14 connected by a transporttube 13 having a switching valve 8f. When hydrogen gas is collected, anLaNi₅ hydrogen absorbing alloy is entered into the generated gas storagevessel 14. While the cells are treated by the treating fluid, either theswitching valve 8b of the gas supplying tube or the switching valve 8dthereof connected to either the treating chamber 1a, or the treatingchamber 1b under operation, is opened, and furthermore the switchingvalve 8e is opened, and also the pump 12 is driven to circulatenitrogen.

The cells treated in this embodiment are five rectangular type 30 Whlithium secondary batteries each having the dimension of 50 mm×80 mm×40mm, in which LiCoO₂ is used as the positive electrode, an Li alloy isused as the negative electrode, and organic electrolytic solution inwhich LiPF₆ is dissolved is used as the electrolyte. A stainless expandmetal having a thickness of 0.1 mm was used as a holder. These cells arecompletely discharged outside the cell treating apparatus, and theswitching plate 3a is opened to position the cells into the preparingchamber 2a. The pump 18a is driven to exhaust air existing in thepreparing chamber from the gas exhausting tube 16a. Next, after theswitching valve 17a is closed, the switching valve 8a is opened toconduct nitrogen gas into the preparing chamber 2a. The switching plate4a is opened, and the cells 15 are positioned under the cell crashingmachine 19 equipped with the diamond cutter. Here, the diamond cutter ofthe cell crashing machine 19 is operated to cut off the upper portionsof the cell vessels, to which the electrode terminals are attached. Theupper portions of the cut cell vessels are taken out and then the cellconstructive members are derived from the cut cell vessels. Hexane issprayed by the sprayer 24a from the treating fluid storage vessel 21afor storing therein hexane via the switching valve 22a, and the treatingfluid transport pump 23a, whereby the electrodes, the separators and theinside portions of the cell vessels, into which the electrolytic fluidshave been absorbed, are cleaned. After the cleaning operation is carriedout, the negative electrodes are cut into small components by way of therotary type cutter mixer, and these small components are stored into thestorage vessel 20 with the bottom on which a mesh is mounted, and alsoboth the cell vessels and the cell constructive components other thanthe negative electrodes are positioned on the belt conveyer near thestorage vessel 20. The disposal cleaning fluid is stored into thedisposal treating fluid storage vessel 28a by opening the switchingvalve 26b. The treating fluids used in the treating chamber 1a are1-propanol and ethanol, which are stored into the treating fluid storagevessels 21b and 21c, respectively. A mixing ratio of 1-propanol toethanol is controlled by adjusting the switching valves 22b and 22chaving the flow-rate adjusting functions. The treating fluids aresupplied by the pump 23b from the sprayer 24b via the treating fluidsupplying tube 25b into the treating chamber 1a. First, the switchingvalve 22c connected to the ethanol storage vessel 21c is closed, and theswitching valve 22b is opened to spray 1-propanol from the 1-propanolstorage vessel 21b by the sprayer 24b, so that the lithium alloy in thenegative electrodes stored in the storage vessel 20 is treated.Subsequently, the switching valve 22c of the ethanol storage vessel 21cis gradually opened, and at the same time, the switching valve 22b ofthe 1-propanol storage vessel 21b is gradually closed, so that ethanolconcentration within the treating fluid is increased. The switchingvalve 22b is completely closed, and only ethanol is supplied from thetreating fluid storage vessel 21c to furthermore treat the negativeelectrodes. In this case, 1-propanol was used by 3 l and ethanol wasused by 4 l, and also the treating time was 1.5 hours.

With employment of the nitrogen gas supplying system constructed of theswitching valve 8c and the gas supplying tube 7c, and also the gasexhausting system constructed of the switching valve 17b, the pump 18b,and the gas exhausting tube 16b, the inside of the preparing chamber 2bis brought into a dry nitrogen atmosphere in a similar manner to thepreparing chamber 2a. Thereafter, the switching plate 4b is opened totransport the storage vessel 20 for storing the negative electrodes andother cell constructive components to the treating chamber 2b.Subsequently, the switching plate 4b is closed and the switching plate4c is opened, whereby both the storage vessel 20 for storing thenegative electrodes and the other cell constructive components are movedjust under the sprayer 24c. The ethanol solution containing 10% of wateris conducted from the treating fluid storage vessel 21d into thetreating chamber 1b, so that the lithium alloy contained in the negativeelectrode is completely brought into the inert state. The treating fluidused in the treating chamber 1b was 2 l and the treating time was 0.7hours. After the treatment has been accomplished, the inside of thepreparing chamber 2c is brought into a dry nitrogen atmosphere byemploying the nitrogen gas supplying system constructed of the switchingvalve 8e and the gas supplying tube 7e, and also the gas exhaustingsystem constructed of the pump 18c and the gas exhausting tube 16c in asimilar manner to that of the preparing chamber 2a. Thereafter, thestorage vessel 20 for storing the negative electrodes and the cell partsother than the negative electrodes are taken out from the preparingchamber 2c.

By the above-described operations, the treatment time of the five 30 Whlithium secondary batteries was approximately 3.5 to 3.8 hours. Theentire volumes of 1-propanol and ethanol required to treat the negativeelectrodes were 3 l and 6 l, respectively. As a result, even such a cellhaving an energy capacity 10 times higher than that of the lithium cellstreated in FIG. 1 and FIG. 2, could be effectively treated as the inertconditions by utilizing the cell treating apparatus according to thisembodiment. The disposal treating fluid are stored from the respectivetreating chambers into the separate vessels, and then lithium of 60% andlithium of 30% could be collected from the respective proposal treatingfluid storage vessels 28b and 28c. As described above, cost of thecondensing steps for the disposal fluids may be reduced by selecting thecell treating fluids which are to be reproduced.

Embodiment 9

FIG. 4 is a cell treating apparatus where three sets of independenttreating fluid supplying systems and an exhausting system are installedto the apparatus of FIG. 1. Two sheets of compartment plates 30a and 30bare provided on the upper portion of the treating chamber 1 to reservethree treating-fluid supplying regions. Three disposal treating-fluidexhausting tubes 27a, 27b, 27c capable of independently collecting thetreating fluids which have been used in the comported regions, weremounted. A switching valve 26a and a switching valve 26b were mounted onthese exhausting tubes, respectively. Hexane used as an electrolyticfluid cleaning purpose is stored into the treating fluid storage vessel21, and both ethanol for decomposing the negative electrode and ethanolcontaining water of 10 wt % for decomposing the negative electrode arestored into the treating fluid storage into the treating fluid storagevessels 21b and 21c, respectively. Dry nitrogen gas to be supplied tothe treating chamber 1 and the preparing chambers 2a and 2b, wasconducted from the gas storage vessel 6 into the apparatus. Lithiumcells handled in this embodiment are 5 pieces of rectangular 30 Whlithium secondary batteries with the dimension of 50 mm×80 mm×40 mm,having the same specification as in the embodiment 8. First, the cells15 were completely discharged outside the cell treating apparatus ofFIG. 4, and the resultant cells 15 were transported inside the treatingchamber 1 in accordance with the same sequence as in the embodiment 1,and then positioned at centers of the compartment plate 30a and theswitching plate 4a. Here, the upper portions of the cell vessels are cutout by employing the cell crashing machine 19 equipped with the diamondcutter to remove the upper vessels of the cells, so that the cellconstructive members are taken out. The electrolytic fluid attached tothe separators, cell vessels and electrodes was washed away by supplyinghexane from the sprayer 24a. The disposal cleaning fluid was stored fromthe fluid exhausting tube 27a into the treating fluid storage vessel28a. The cleaned negative electrodes were cut into small components byutilizing the rotary type cutter mixer, and the resulting smallcomponents were stored into the storage vessel 20 with the bottom onwhich a mesh is provided. Other cell members are kept on the beltconveyer 5. The belt conveyer 5 is driven to move the storage vessel 20just under the sprayer 24b, so that ethanol present in the treatingfluid storage vessel 21b is sprayed from the sprayer 24b. During thetreatment, the heater 29 was not operated and ethanol was not heated.The supplying amount of ethanol was 5 l and the treatment time required1.2 hour in this step. After approximately 0.7 hour has passed from thecommencement of the treatment, white lithium alcoholate was depositedand the hydrogen generating speed became delayed. Next, both the storagevessel 20 for storing therein the negative electrodes and other cellcomponents were put on the belt conveyer 5 and transported under thesprayer 24c. Here, an ethanol mixture fluid containing water of 10 wt %was sprayed from the treating fluid storage vessel 21c to the negativeelectrodes. The alloy which is contained in the negative electrodes andhas not yet been reacted, was again started to be decomposed, so that itcould be observed that hydrogen gas was produced. The volume of thetreating fluid used in this operation was 2 l and the treatment time was0.5 hours. Next, after the atmosphere of the preparing chamber 2b hadbeen changed into dry nitrogen atmosphere, the switching plate 4b wasopened to move the storage vessel 20 and the electrode members to thepreparing chamber 2b. Subsequently, after the switching plate 4b wasclosed and the switching plate 3b was opened, all of the treated cellmembers were derived. The time required to bring the negative electrodesof the five 10 Wh lithium secondary cells into the inert condition was2.7 to 2.8 hours, which were shorter than that the embodiment 7. Theoverall volume of ethanol required to process the negative electrodeswas approximately 7 l. Since the amount of hydrogen generated in alltreatment steps was at the most 100 to 170 ml per minute, thelarge-sized lithium cells could be treated under safety condition byemploying the apparatus of FIG. 4. The disposal fluids stored in thedisposal treating fluid storage vessel 28a was vacuum-evaporated, sothat 95% of the total amount of LiPF₆ contained in the five cells couldbe collected. The disposal fluids obtained from the vessels 28b and 28cwere evaporated, and 87% of lithium contained in all of the cells whichwas treated by the electric refinery could be collected. The lithiumcollecting ratios were 55% for the vessel 28b and 32% for the vessel28c. In accordance with the present embodiment, when even such cellshaving the energy capacity 10 times higher than that of the lithiumsecondary cells treated in FIG. 1 and FIG. 2 were continuously treatedby the cell treating apparatus of FIG. 4, the treatment time per asingle cell could be shortened, and hydrogen produced during the celltreatment could also be collected into the generated gas storage vessel14 into which the LaNi₅ alloy has been entered, so that safetyconditions of the cell treatment could be maintained. Since the disposaltreating fluids could be stored from the respective treating chambersinto the respective tanks, the evaporating steps of the vessel 28b couldbe made simple, and also cost of the condensing steps for the disposalfluids could be reduced by separately collecting the disposal fluids.

Embodiment 10

FIG. 4 is a cell treating apparatus where three sets of independenttreating fluid supplying systems and an exhausting system are installedto the apparatus of FIG. 1. Two sheets of compartment plates 30a and 30bare provided on the upper portion of the treating chamber 1 to reservethree treating-fluid supplying regions. Three disposal treating-fluidexhausting tubes 27a, 27b, 27c capable of independently collecting thetreating fluids which have been used in the comported regions, weremounted. A switching valve 26a and a switching valve 26b were mounted onthese exhausting tubes, respectively. 1-Methyl-2-pyrrolidone used as anelectrolytic fluid cleaning purpose is stored into the treating fluidstorage vessel 21a, and both propanol of 99% purity for decomposing thenegative electrode and water for decomposing the negative electrode arestored into the treating fluid storage into the treating fluid storagevessels 21b and 21c, respectively. Dry nitrogen gas to be supplied tothe treating chamber 1 and the preparing chambers 2a and 2b, wassupplied from the gas storage vessel 6 into the apparatus. Lithium cellshandled in this embodiment are 5 pieces of rectangular 30 Wh lithiumsecondary batteries with the dimension of 50 mm×80 mm×40 mm, having thesame specification as in the embodiment 8. First, the cells 15 werecompletely discharged outside the cell treating apparatus of FIG. 4, andthe resultant cells 15 were transported inside the treating chamber 1 inaccordance with the same sequence as in the embodiment 1, and thenpositioned at centers of the compartment plate 30a and the switchingplate 4a. Here, the upper portions of the cell vessels are cut out byemploying the cell crashing machine 19 equipped with the diamond cutterto remove the upper vessels of the cells, so that the cell constructivemembers are taken out. The electrolytic fluid attached to theseparators, cell vessels and electrodes was washed away by supplying1-methyl-2-pyrrolidone from the sprayer 24a. The disposal cleaning fluidwas stored from the fluid exhausting tube 27a into the treating fluidstorage vessel 28a. The cleaned negative electrodes were cut into smallcomponents by utilizing the rotary type cutter mixer, and the resultingsmall components were stored into the storage vessel 20 with the bottomon which a mesh is provided. Other cell members are kept on the beltconveyor 5. The belt conveyor 5 is driven to move the storage vessel 20just under the sprayer 24b, so that 99% propanol present in the treatingfluid storage vessel 21b is sprayed from the sprayer without opening thevalue 22c. During the treatment, the heater 29 was not operated and saidpropanol was not heated. The supplying amount of the treating liquid was1.5 l and the treatment time required 0.3 hour in this step. Afterapproximately 0.3 hour has passed from the commencement of thetreatment, white lithium alcoholate was deposited and the hydrogengenerating speed became delayed. The valve 21c was opened to supply thepropanol and water mixture solution on the negative electrodes. Thewater content in the mixture fluid was increased up to 50% to make thelithium deactivation reaction take place again. The supplying amount ofthe propanol and water mixture solution was 1.5 l and the treatment timerequired 0.3 hour in this step. The supplying amount of the propanol was5 litter and the treatment time required 1.0 hour in this step. Afterapproximately 0.6 hour has passed from the commencement of thetreatment, white 1 lithium alcoholate was deposited and the hydrogengenerating speed became delayed. Next, both the storage vessel 20 forstoring therein the negative electrodes and other cell components wereput on the belt conveyor 5 and transported under the sprayer 24c. Here,water was sprayed from the treating fluid storage vessel 21c to thenegative electrodes. The alloy which is contained in the negativeelectrodes and has not yet been reacted, was again started to bedecomposed, so that it could be observed that hydrogen gas was produced.The volume of the treating fluid used in this operation was 2 l and thetreatment time was 0.1 hours. Next, after the atmosphere of thepreparing chamber 2b has been replaced with dry nitrogen atmosphere, theswitching plate 4b was opened to move the storage vessel 20 and theelectrode members to the preparing chamber 2b. Subsequently, after theswitching plate 4b was closed and the switching plate 3b was opened, allof the treated cell members were derived. The time required to bring thenegative electrodes of the five 30 Wh lithium secondary cells into theinert condition was 2.0 to 2.1 hours, which were shorter than that theembodiment 9. The overall volume of 99% propanol solution required toprocess the negative electrodes was approximately 7 l. Since the amountof hydrogen generated in all treatment steps was 200 ml or less perminute, that is, the concentration of hydrogen gas generated is kept at4% or less in the treating chamber, the large-sized lithium cells couldbe treated under safety condition by employing the apparatus of FIG. 4.The disposal fluids stored in the disposal treating fluid storage vessel28a was vacuum-evaporated, so that 95% of the total amount of LiPF₆contained in the five cells could be collected. The disposal fluidsobtained from the vessels 28b and 28c were evaporated, and 87% oflithium contained in all of the cells which was treated by the electricrefinery could be collected. The lithium collecting ratios were 55% forthe vessel 28b and 32% for the vessel 28c. In accordance with thepresent embodiment, when even such cells having the energy capacity 10times higher than that of the lithium secondary cells treated in FIG. 1and FIG. 2 were continuously treated by the cell treating apparatus ofFIG. 4, the treatment time per a single cell could be shortened, andhydrogen produced during the cell treatment could also be collected intothe generated gas storage vessel 14 into which the LaNi₅ alloy has beenentered, so that safety conditions of the cell treatment could bemaintained. Since the disposal treating fluids could be stored from therespective treating chambers into the respective tanks, the evaporatingsteps of the vessel 28b could be made simple, and also cost of thecondensing steps for the disposal fluids could be reduced by separatelycollecting the disposal fluids.

With employment of the cell treating method and the cell treatingapparatus, according to the present invention, the lithium cells can beeffectively treated under safety conditions, and also the valuablesubstances including lithium contained in the cells can be collected.

What is claimed is:
 1. A method for treating a cell having an electrodecontaining lithium comprising the steps of:a step of exposing theelectrode; a step of treating the electrode thus exposed with a firsttreating reagent which is reactive to the lithium, the first treatingreagent comprises a protonic organic solvent or a first mixture of theprotonic organic solvent and water; a step of treating the electrodethus treated with the first treating reagent with a second treatingreagent which is more reactive to the lithium than the first treatingreagent, the second treating reagent comprises a second mixture of theprotonic organic solvent and water, the second treating reagent isricher in water than the first mixture.
 2. A method according to claim1, wherein said first and second treating reagents comprise a 0.99:0.01to 0.9:0.1 mixture of protonic organic solvent and water by weight.
 3. Amethod according to claim 2, further comprising a step of controlling atemperature of said electrode at a temperature of 80° C. or less.
 4. Amethod according to claim 1, further comprising a step of recovering theused first and second treating reagents and a step of collecting thetreated electrode.
 5. A method for treating a cell having an electrodecontaining lithium in a cell treating apparatus comprising the stepsof:a step of exposing the electrode; a step of treating the electrodethus exposed with a first treating reagent which is reactive to thelithium to generate hydrogen; a step of treating the electrode thustreated with the first treating reagent with a second treating reagentwhich is more reactive to the lithium than the first treating reagent togenerate the hydrogen, a step of controlling hydrogen content in thecell treating apparatus under 4%.
 6. A method for treating a cell havingan electrode containing lithium in a cell treating apparatus comprisingthe steps of:a step of exposing the electrode; a step of treating theelectrode thus exposed with a first treating reagent which is reactiveto the lithium to generate hydrogen; a step of treating the electrodethus treated with the first treating reagent with a second treatingreagent which is more reactive to the lithium than the first treatingreagent to generate the hydrogen, a step of controlling a temperature inthe cell treating apparatus under 100° C.
 7. A method according to claim6, wherein the temperature in the cell treating apparatus is controlledto be under 40° C.
 8. A method for treating a cell having an electrodecontaining lithium and a case, the method comprising the steps of:afirst step of opening the case of the cell to expose the electrode; asecond step of contacting the electrode thus exposed in the first stepwith a first treating fluid containing a solvent which dissolves abinder of the electrode; a third step of contacting the electrode thustreated in the second step with a second treating fluid comprises aprotonic organic solvent or a first mixture of the protonic organicsolvent and water; a fourth step of contacting the electrode thustreated in the third step with a third treating fluid comprises a secondmixture of the protonic organic solvent and water, the second mixture isricher in water than the first mixture; a fifth step of recovering thefirst treating fluid, the second treating fluid and the third treatingfluid used in the second, third and fourth steps, respectively; a sixthstep of collecting the treated electrode of the cell.